Cleavers, Galium aparine
Weed Control Options 
Life Cycle
Annual, Winter annual.Propagation
Reproducing only by seed.Stems
Stems weak or reclining, 10-121cm long, square in cross-section with strongly ribbed corners, with very short, downward- or backward-pointing, firm, hair-like and curved bristles (a).Leaves
Leaves usually 3 to 8 in a whorl (b), linear, tapering at the base, mostly 1-8cm long, with bristles at the pointed tip (c), somewhat hairy on both surfaces and with many very short, backward-pointing bristles on the margins. These tiny hook-like bristles on stems and leaves cause them to cling together in masses and to cling to clothing, skin or fur, hence the common name, "cleavers."Flowers and Fruit
Inflorescence mostly 1- to 5-flowered. The flowers are very small and soon replaced by the small spherical fruits (d). The fruits are bristly, 1.5-4mm in diameter. Flowers from May to August.Roots and Underground Structures
Fibrous root system.Habitat
Cleavers is found in southern Ontario in woods, meadows, compost heaps, gardens and fields, and along roadsides and riverbanks.Distinguishing Features
It is distinguished by its square, weak, clinging stems, its bristle-tipped leaves that also cling with backward-pointing bristles on the margins, and all leaves arranged in whorls of 3 to 8 at each node of the stem.Media Items
Figure 1: A. Lower and upper parts of a mature plant. B. Portion of stem enlarged to show the backward pointing bristles (a). Top
Figure 2: Cleavers small seedling. Top
Figure 3: Cleaver flower and stem (b,c). Top
Figure 4: Cleaver stem with seed pods (d). Top
Figure 5: Leaf whorl with bristles (b) on the margins of each leaf and its pointed tip. Smooth bedstraw will not have bristles on its leaves. Top
Figure 6: Young seedling plant. Top
Figure 7: Mature plant. Top
Figure 8: Top
Figure 9: Fibrous root system of cleavers. Top